In my opinion, the fact of EM seeming different from older seasons is that, it is a abuse response. Some people really want to escape from abuse they experience but whenever they actually get out, they want to go back at it again. They don't actually crave the abuse, but since it is one thing they have familiarity with, at one point they return back to it. I take it as, EM finally got out and away from all of these, finally got them to stay away from him. However, after a while he wanted to go back to that familiarity again, not necesserily the abuse but maybe the familiarity of having a Rick and having adventures together. But also, he didn't want to be in the end of it. Therefore he used the Omegadevice to stay on top while still going back to that toxicity. He also specifically went to C-137, as he knew the guy from before + he knew the fact that C-137 somewhat cared about his family (the family he never got to have in his universe due to Prime Rick) so he can use that as a leverage.
i definitely can't discard this theory as a possible explanation!
but neither can i fully discard these other theories i've seen, including but not limited to:
EM couldn't overcome the genetic predisposition to needing Rick that all Mortys are engineered to have
EM was acting the whole time and getting arrested by the time cops is part of his master plan
EM never forgave Morty Prime for not taking his offer and so wanted to steal his Rick
EM got fucking bored
point is: it's absolutely valid (and fun!) to theorize about hidden character motivations, i often do it myself. In my opinion, however, this particular motivation should not have been hidden in the first place. but YMMV. shrug.
